Wall scraper



Oct. 31, 1939.

WALL SCRAPER m m w [M awn awuw f w d: v

m w w W Oct. 31, 1939. s. D. JOHNSON El AL WALL SCRAPER Filed Feb. 23, 1938 2 Sheets-Sheet 2 N H G W R m f iii) Patented Got. 31, 1939 UNlTED sTArs mrsurorrlcs WALL SCRAPER.

Glenn D. Johnson, Compton, and Egon R. Lindgren, Huntington Park, Calif., assignors to Baash-Ross Tool Company, Los Angeles, Calif, a corporation of California Application February 23, 1938, Serial No. 192,044

8 Claims. (01. 255 m a tool of the character mentioned in which the driller or operator is made aware of the projection or actuation of the cutting elements when their projection is complete.

hydraulically actuated wall scraper in which the circulation of the fluid through the operating string and the tool is started simultaneously with complete projection of the cutting .elementsto inform the driller of this fact and to assure the proper flushing action at the cutting elements. Another object of this invention is to provide a wall scraper of the character mentioned in which the circulation of fluid cannot be cut oif, interrupted or excessively restricted following actuation of the cutting elements.

Another object of this invention is to provide a wall scraper of the character mentioned in which the circulation fluid is fully handled by the piston element following actuation of the cut-- detailed description of a typioalpreferred form of the invention, throughout which description reference is made tothe accompanying drawings in which:

Fig. i is a side elevation of the tool provided by the invention with a portion broken away to illustrate one of the cutting elements in its retracted position. Fig.2 is an enlarged longitudinal detailedscctional view of the principal parts of the tool showing the piston and the cutting elements in the normal positions; Fig '3 is an enlarged side elevation of the valve removed from the tool with portions broken away to show a latch and illustrating the spring and washers in cross section. Fig. 4 is a view similar to Fig. 3 showing the cutting elementsin the projected position. anclFigs. 5 and 6 are enlarged transverse detailed sectional view taken as indicated by lines 5-5 and 6 6 respectively,- on Fig. 4.

, The improved underreaming tool or wall scraper of the present invention includeagenorally, a body it, a plurality of cutting elements ll carried by the body ill, a tubular mandrel iii shift-able in the body iii to project the cutting elements ii and a control 53 cooperable with the mandrel E2 to eiiect its positive actuation by fluid pressure and providing for the substantially free passage of circulation fluid throughthe tool when 5 the projection of the cutting elements H is complete or substantially complete.

The body W of the tool is adapted to beconnec'ted with a tubular operating string such as a string S of drill pipe. Thebody ill is a hollow M. is provided at its upper end with a tapered. screw-threaded pin 35 for facilitating the corn nection of the tool with the strings. The upper body section it may be a simple tubular member of uniform diameter and of substantially the same diameter as the string S. A tapered socket 3 it may be provided in the lower end of the section I 4.

' The lower body section i5 is an elongate member secured to the lower end of the section I4. In

practice the member IE may be provided with a tapered pin ill threaded into the socket iii. The two body sections Hi and it may be of the same external diameter. The section 15 is provided between its ends with circumferentially spaced longitudinal enlargements or ribs It. In the form of the invention disclosed there are three equally spacedribs It. The tool may carry a suitable bit B. As shown in the drawings the bit 13 may be secured to the lower end of the section It by a suitable threaded connection is. A longitudinal bore or cylinder opening 26 extends centrally through the. section l5 from the upper end of its pin ll.

in the upper body section. I i. In the preferred construction the opening?!) terminates at a point abov'ethe lower end of the section I5;

The opening 20 has a diameter consid- Y erably less than the diameter of the opening 2W Elongate openings or slots 2| are provided in the body section I5 to carry or receive the cutting elements II. The slots 2| extend outwardly from the cylinder opening 20 and pass through the ribs it) to the external surfaces of the ribs. There is one slot ZI extending through each rib I8. In accordance with the invention the side walls of the slots H are tangent to circles concentric with the longitudinal axis of the body I0. These tangential side walls of the slots 2i are preferably flat and vertical. The lower walls of the slots 2! may be flat and horizontal while the upper Walls 22 of the slots 2! are preferably inclined downwardly and outwardly with respect to the vertical axis of the tool.

The cutting elements I! are provided to act on the earth formation to enlarge the well bore below the lower end of a casing set in the well. In accordance with the broader aspects of the invention the cutting elements I I may be varied in character or type. In the typical embodiment of the invention illustrated the cutting elements II are in the nature of shear type or drag type blades. The several blades or elements I I may be identical. The cutting elements II are flat platelike members and are pivotally supported in the slots 2! and are movable or swingable from re tracted positions such as shown in Figs. 1 and 2 of the drawings to projected positions such as shown in Figs. 4 and 5. In the arrangement illustrated in the drawings transverse openings 23 are provided in the ribs It to intersect the slots 2! and pins 24 are driven or otherwise fixed in the openings 23 to pass through transverse openings 25 in the cutting elements iI. Thus the cutting elements II are supported for pivotal movement about individual horizontal or transverse axes.

The inner ends of the cutting elements I I may be curved about their pivotal axes. The upper and lower edges 26 and 2'! respectively, of the elements II may be substantially parallel while the outer ends 28 of the elements are inclined or pitched to join the lower edges 2'? at points 29. These points 29 may be somewhat flat to be substantially horizontal when the cutting elements H are projected to their active positions. The outer edges 28, the lower edges 2? and the points .29 may be suitably sharpened and may be hardfaced. It will be observed that the cutting elements i I pivoted in the tangential slots II have a desirable lead with respect to the direction of rotation of the tool to be particularly eifective in their cutting action.

The mandrel I2 is controlled or actuated by the pressure on the drilling fluid or circulation fluid to swing the cutting elements II to their active positions. The mandrel I2 is in the nature of a tubular piston shiftable in the opening 120 of the body section I5. The mandrel i2 is of sufficient length to project a substantial distance upwardly into the body section M and yet have a substantial portion received in the opening 20. The central longitudinal opening 3!! of the mandrel l2 extends completely through the mandrel to receive the fluid from the interior of the body section I4 and to discharge the circulation fluid at or adjacent the above-described slots 2i. The mandrel opening 39 is sufficiently large in diameter to correctly handle the circulation fluid necessary for the flushing of the cutting elements II.

A head or piston P is provided on the upper end of the mandrel I2 to slidably seat with the interior of the body section Id. The piston P may comprise a lower plate or member 3! seating downwardly against a shoulder 32 on the mandrel I2, a cup leather 33 at the upper side of the member SI and a nut 34 threaded on the mandrel I2 and engaging downwardly against the cup leather 33. The cup leather 33 is positioned and designed to effectively seal with the wall of the opening Zi when fluid pressure is applied to the upper side of the piston P. It will be observed that the piston P has an effective diameter considerably greater than that of the opening 3 so that fluid pressure in the opening Zi is operable to move the mandrel i2 downwardly. Bleeder ports 35 are provided in the wall of the section I4 to communicate with the opening 21 adjacent the pin I! to allow free downward movement of the piston P in the opening 2!. The piston member 3I is adapted to engage the upper end of the pin I? to limit the downward travel of the mandrel I2.

In accordance with the invention the mandrel I2 has active cooperation with the cutting elements l I. It is a feature of the invention that the operative relationship between the mandrel I2 and the cutting elements i I is such that levers, links, pivotal connections and the like are un necessary and the mandrel has direct cooperation with parts on the cutting elements. Spaced downwardly projecting fingers 3B are provided on the lower end of the mandrel I2. VJhen three cutting elements II are employed there are three equally spaced fingers 38. The lower ends of the fingers 36 are suitably rounded or convex. The opening 3t continues downwardly through the series of fingers 36, that is, the inner surfaces oi the fingers are flush with the wall of the opening 38 so that the fingers do not restrict or interfere with the downward flow of fluid. A tail or lug 3? is provided on the inner end of each cutting element II and is engageable by a finger The lugs 31 may be integral parts of the cutting elements iI. Considering the cutting elements II to be in their retracted positions, the upper sides 38 of the lugs 31 slope downwardly and outwardly relative to the central vertical axis of the tool. The upper sides 38 of the lugs 376 are flat and smooth so that the fingers 36 have effective camming cooperation with the lugs. The lower ends or edges of the lugs 37 may slope downwardly and outwardly considering the elements I i to be in. their retracted positions. The inner sides of the lugs 31 are concave or grooved to be flush with or to be in alignment with the wall of the opening 38 when the elements H are in. their extended positions so that the lugs do not interfere with the downward flow of fluid from the opening.

It is believed that it will be apparent how the fingers 36 of the mandrel I2 cooperate with the lugs 3i during downward movement of the mandrel to swing the cutting elements i! from their retracted positions to their expanded or extended cutting positions. It is to be observed that the cutting elements i i occupy vertical planes tangent to a circle concentric with the vertical axis of the tool so that a desirable leverage or mechanical advantage is obtained for the actuation of the cutting elements. The parts are related so that the piston member 3| approaches or cooperates with the upper end of the pin II when the cutting elements I I reach the positions where their upper edges 26 approach or cooperate with the upper walls 22 of the slots 2!. The upper edges 26 of the cutting elements II are adapted to have extensive fiat engagement with said upper walls 22.

Means is preferably provided to prevent turningof the mandrel l2 to maintain the fingers 38 in correct relation to the lugs 38. One or more circumferentially spaced keys it are set in the wall of the opening ill to beslidably received in keyways M in the mandrel l2. The keys 46 are preferably fixed or held in grooves 42 in the wall of the opening it}. In the case illustrated the keys it engage against the lower ends of the grooves l2 and the metal of the. pin H is peened over at it to engage downwardly against the upper ends of the keys. The lower walls of the keyways M are cooperable with the lower ends of the keys .8 to limit the upward travel of the mandrel Ill.

The control i3 is an important feature of the invention. Thecontrol It provides for the positive actuation of the cutting elements H bythe mandrel l2 and provides a signal to the driller or operator to indicate the projection or expansion of the cutting elements H. In the preferred construction the control it is housed in the upper bodysection it. The control lt comprises what we will term a valve M. The valve M is in the form of an elongate member provided at its lower end with a head 45. The valve M is arranged centrally and longitudinally in the section hi and is guided for vertical movement by a web or guide at. The guide 46 may be a ring-like member threaded in the opening 2l and is provided with a central vertical opening ll slidably passing the valve fi l. The guide 46 is perforated to provide for the free flow of.

circulation fluid through the opening Al The valve M is co-axial. with the mandrel l2 and its head it is cooperable with a valve seat is on the mandrel.

. extending into the opening 3% and'may have a flange dd clamped against the upper end of the' mandrel Why the nut 3d. The valvehead 45 is adapted to engage downwardly against the upper end of the seat 48 to close ofi the opening 36. The head i5 is pointed ort'apered to extend downwardly into the seat 48 and to cooperate with a suitable bevelled surface on the seat. i

When the parts are in their initial positions just prior to expansion of the cutting element l I, the mandrel i2 is in the position where its piston P is some distance above the pin ll and the valve mandrel l2 and its seat 48 when the mandrel.

reaches or approaches a position where the cut ting elements l l are fully extended. This mechanism includes a helical spring 58 carried by the valve A l. The spring 5%! surrounds the upper portion of the valve M and is located above the guide 46. A nut 5! may be threaded on the up per end of the valve id and the upper end of the spring 523 may engage against a washer 5i bearing upwardly against the lower end of the nut.

The lower end of the spring 58 cooperates with a ring 53. The ring 53 is slidable or shiftable on the valve id and is provided with an upturned rim 54 for holding the spring 50 centralized.

The seat it may be a tubular'member definitely limit the inner wall or surface of the ring 53.

Aiatch. 55 isprovided. on the. valve Ml to initially or normally hold the ring 53 in a position where thespring fall is under compression or is contracted. The latch55 may be arranged in a with the lower side of the ring 53*holds the ring against downward movement on the valve 44 and therefore maintains the spring 50 under substantial compression between the ring and the washer 52. A shoulder 58 may be provided on the upper end of the latch 55 to cooperate with the internal surface of the ring 53 to prevent premature displacement or disengagement of the latch from the ring. j

The latch 55 is positioned so that its inclined outer edge cooperates with the wall of the opening ll during downward movement of the valve M with the mandrel I 2. This engagement of the latch 55 with the wall ofthe opening 4! occurs when the mandrel l2 approaches the position where the cutting elements ll are fully, actuated and occurs when the lower side of the ring 53 approaches or engages the upper side of the guide 45. The engagement'of the sloping outer edge of the latch 55 with the wall of'the opening t? results in retraction of the latch substantially simultaneously with the cooperation of the ring 53 with the upper side of the guide 56. The release of the latch 55 from the ring occurs when the piston P is a short'distance above the upper end of the pin H and the cutting elements ii are substantially fully projected. The release of the latch 55'from the ring 53 frees the valve M from the ring 53 sothat the spring 50 reacting against the ring (now seated on the guide 46) and reacting against the washer 52 suddenly moves the valve 44 upwardly; The broken lines in Fig. 4 indicate the lowermost position attained by the valve 44. When this position is attained by the valve 44!, the latch 55 is released, as described above, and the spring 50 moves the valve 44 upwardly away from the seat 33 and the piston P to allow or initiate the discharge of the fluid under pressure downwardly through the opening 30 of the mandrel l2. This i initiation of the circulation of fluid is accompanied by a starting of the pumps handling the fluid so that the driller is automatically informed of the actuation of the cutting elements II. A

collar fill may be fixed to the valve 44 above the 1 ring 53 to cooperate with the ring and cause the ring to engage against the guide 48 and thereby downward travel of the valve 44.

The control it further includes latch means for retaining the valve 44 in the up or released position following its retraction by the spring '58 as just described. A longitudinal slot BI is provided in the ring 53 and a latch 62 is arranged in the slot. The latch 62 is pivotally supported on a pin 63 extending transversely through the slot 6!. pivot pin 63 and is adapted to project from the A spring M is secured to the ring 53 and cooperates with the latch 62 to yieldingly urge the latch inward- 1y. The latch 62 may normally yieldingly bear.

The latch 62 projects upwardly from its groove 9 is located to move upwardly through the opening 4'! to a position above the guide 46 when the spring 50 shifts the valve 44 upwardly as described above. The latch 62 is cooperable with the groove 9 when the groove moves through or into the ring 53 seated on the guide 46 as described above. The spring 64 automatically moves the latch 62 into cooperation with the groove 9 so that the groove and latch cooperate as illustrated in Fig. 4 of the drawings. This cooperation of the latch 62 with the groove 9 holds the valve 44 in its retracted position and positively prevents downward movement of the valve following the actuation of the cutting elements H.

In the operation of the tool the body NJ carrying the bit B may be secured to the lower end of the string S and run into the well on the string. The parts are in the positions illustrated in Fig. 2 of the drawings when the tool is run into the well. In the event that the well contains liquid the string S may be run into the well wet, that is, filled with liquid so that the hydrostatic forces on the valve 44 and mandrel l2 are balanced. In most instances, however, it may be preferred to run the tool into the well dry so that the well liquid flows up through the opening and raises the valve 44 to enter the string S. The hydrostatic pressures acting on the lower end of the mandrel l2 may also raise the ma. drel. This upward movement of the mandrel I2 is limited by the lower walls of the keyways 4i cooperating with the keys 40. The hydrostatic pressure in the well may be sufficient to raise the valve head from its seat 48 when the upward movement of the mandrel l 2 has stopped. When the pressures on the mandrel l2 and valve 44 have become equalized the valve 44 and the mandrel I2 return by gravity to the positions illustrated in Fig. 2.

When the well scraper or tool has reached a position beyond the lower end of the well casing rotation of the tool is begun. The fluid in the string S is then put under pressure by the pumps. The fluid pressure in the opening 2! acts downwardly against the piston P and the valve 44 to move the same downwardly. During the downward movement of the mandrel [2 the fingers 35 of the mandrel cooperate with the lugs 31 to swing the cutting elements II to their projecting positions. The expanding cutting elements I I on the rotating tool cut clearance in the earth formation at the side wall of the well. The downward movement of the mandrel l2 and the valve 44 continues until the latch moves through or into the opening 41. The engagement of the wall of the opening 41 with the latch 55 retracts the latch and, upon retraction of the latch from the ring 53, the spring 50 reacting against the upper side of the guide 46 through the medium of the ring 53 suddenly moves the Valve 44 upwardly. This moves the valve head 45 away from the seat 48 and allows the fluid under pressure to flow downwardly through the opening 30. The piston P and the mandrel 42 may continue to move downwardly. The fluid is free to discharge into the well through the slots 2| at or adjacent the plane of action of the cutting elements II. The piston P and the mandrel 12 may continue to move downwardly under the action of the fluid pressure after the valve 44 is retracted as just described. During the upward movement of the valve 44 its groove 9 moves through or into the ring 53 and when the valve approaches its uppermost position the latch 62 pivots inwardly under the action of the spring 64 so that its upper inner corner engages in the groove 9. This latches the valve 44 in its raised position.

The upward movement of the valve 44 away from the piston P and the valve seat 48 allows the circulation fluid to flow downwardly through the opening 3!) and out through the slots 2|. This initiation of the circulation through the tool results in the starting of the pumps and this informs the operator or driller of the projection of the cutting elements II. The rotation of the string S may be continued to cause the cutting elements H to ream or enlarge the bore as desired. During this reaming action the circulation fluid is pumped downwardly through the string S to flow through the openings Zia and 30 to discharge from the slots H. The fluid discharging from the slots 2! effectively cleans and flushes the cutting elements H and may assist in the reaming operation. It will be ob served that the opening 30 is clear and unobstructed following the retraction of the valve 44 and that the circulation fluid may freely flow out through the slots 2|.

The present invention provides a reaming tool or wall scraper in which the cutting elements are positively projected oractuated by a hydrauhe means and in which the driller or operator is made aware of the correct projection of the cutting elements. There is a minimum obstruction to the circulation of fluid through the tool following the projection of the cutting elements ii and the fluid is conducted or handled by the simple tubular mandrel i2 without resorting to the use of special passages and ports in the tool body.

Having described only a typical preferred form and application of our invention we do not wish to be limited or restricted to the specific form and application herein set forth, but wish to reserve to ourselves any modifications or variations that may appear to those skilled in the art or fall within the scope of the following claims.

Having decribed our invention, we claim:

1. A well tool of the character described comprising a body, a cutting element carried by the body for movement from a retracted position to a projecting position, a tubular piston element movable in the body by fluid pressure to project the cutting element, a valve closing the piston element and movable therewith, and means operable to move the valve in a direction opposite to the direction of travel of the piston element to permit flow through the piston element when the cutting element is projected.

2. A weli tool for use on a tubular well string comprising a hollow body having communication with the string, a cutting element carried by the body for movement from a retracted position to a projecting position, a tubular piston element movable downwardly in the body by fluid pressure applied through the string to move the cutting element to a projecting position, a valve in the body closing the piston element and movable therewith during said projection of the cutting element, and means for moving the valve upwardly away from the piston element when the cutting element is projected to initiate the flow of fluid through the piston element.

3. A well tool for use on a tubular well string comprising a hollow body having communication with the string, a cutting element carried by the body for movement from a retracted position to a projecting position, a tubular piston element movable in the body by fluid pressure applied through the string to movethe cutting element to a projecting position, a valve in the body closing the piston element and movable therewith during said projection of the cutting element, and spring means moving the valve away from the piston to allow the fluid to flow therethrough when the cutting element is projected.

4. A well tool for use on a tubular well string comprising a hollow body having communication with the string, a cutting element carried by the body for movement from a retracted position to a projecting position, a tubular piston element movable in the body by fluid pressure applied through the string to move the cutting element to a projecting position, a valve in. the body closing the piston element and movable therewith during said projection of the cutting element,

means for reversing the direction of travel of the valve to move the valve away from the piston to allow the fluid to flow therethrough when the cutting element is projected, and means for subsequently holding the valve in a retracted position.

5. A well toolo-f the character described for use on a tubular well string comprising a hollow body having communication with the string the body having a cylinder opening and spaced lateral slots joining the cylinder opening and lying in planes tangent to a circle concentric with the longitudinal axis of the body, cutting elements pivoted in the slots, and means for swinging the cutting elements to positions where they project from the slots including a tubular fluid conducting piston element movable in said opening by fluid pressure, the lower end of the piston element initially discharging freely into the cylinder opening above the slots and discharging at the slots when the element is actuated, lugs on the inner ends of the cutting elements, and spaced downwardly projecting parts on the lower end of the piston element engaging the lugs to swing the cutting elements when the piston element moves, the slots receiving fluid from the lower end of the piston element and discharging into 65 shiftable in the said second opening and movable to project the cutting element, a piston on the mandrel movable downwardly in the said first opening by pressure applied through the string, a valve closing the tubular mandrel and movable therewith during projection of the cutting element, and means for moving the valve upwardly from the mandrel when the cutting element is projected so that fluid may pass through the mandrel and discharge from the slot.

'7. A wall scraper for use on a tubular well string including a body having an opening communicating with the string and a second opening extending downwardly from the first opening and having a lateral'slot joining said second opening, a cutting element pivoted in the slot to be projected therefrom, a tubular mandrel shiftable in the said second opening and movpart of the Valve, and a latch on the valve normally holding the said member in a position where the spring is compressed and released by engagement with the abutment to permit the spring to react against the abutment to move the valve.

8. A well too-1 for use on a tubular well string comprising a hollow body having communication with the string, a cutting element carried by the body for movement from a retracted position to a projecting position, a tubular piston element movable in the body by fluid pressure applied through the string to move the cutting element to a projecting position, a valve in the body closing the piston element and movable therewith during said projection of the cutting element, a member in the body guiding the valve, and means for retracting the valve from the piston element when the cutting element is projected including spring means for reacting between the valve and the guide member, and latch means controlling the spring means.

GLENN D. JOHNSON.

EGON R. LINDGREN. 

